- 4.14.20

[packages/kernel.git] / kernel-small_fixes.patch

diff --git a/kernel-small_fixes.patch b/kernel-small_fixes.patch
index 01e03aa64da497ac17ba88984c47f9e05ec251da..d4b603499b05f64e51b96e527678c26a94700ef8 100644 (file)
--- a/kernel-small_fixes.patch
+++ b/kernel-small_fixes.patch
@@ -26,74 +26,3 @@
                                exit
                        fi
                done
-
-From 30927520dbae297182990bb21d08762bcc35ce1d Mon Sep 17 00:00:00 2001
-From: Eric Dumazet <edumazet@google.com>
-Date: Wed, 9 Sep 2015 21:55:07 -0700
-Subject: [PATCH] tcp_cubic: better follow cubic curve after idle period
-
-Jana Iyengar found an interesting issue on CUBIC :
-
-The epoch is only updated/reset initially and when experiencing losses.
-The delta "t" of now - epoch_start can be arbitrary large after app idle
-as well as the bic_target. Consequentially the slope (inverse of
-ca->cnt) would be really large, and eventually ca->cnt would be
-lower-bounded in the end to 2 to have delayed-ACK slow-start behavior.
-
-This particularly shows up when slow_start_after_idle is disabled
-as a dangerous cwnd inflation (1.5 x RTT) after few seconds of idle
-time.
-
-Jana initial fix was to reset epoch_start if app limited,
-but Neal pointed out it would ask the CUBIC algorithm to recalculate the
-curve so that we again start growing steeply upward from where cwnd is
-now (as CUBIC does just after a loss). Ideally we'd want the cwnd growth
-curve to be the same shape, just shifted later in time by the amount of
-the idle period.
-
-Reported-by: Jana Iyengar <jri@google.com>
-Signed-off-by: Eric Dumazet <edumazet@google.com>
-Signed-off-by: Yuchung Cheng <ycheng@google.com>
-Signed-off-by: Neal Cardwell <ncardwell@google.com>
-Cc: Stephen Hemminger <stephen@networkplumber.org>
-Cc: Sangtae Ha <sangtae.ha@gmail.com>
-Cc: Lawrence Brakmo <lawrence@brakmo.org>
-Signed-off-by: David S. Miller <davem@davemloft.net>
----
- net/ipv4/tcp_cubic.c | 16 ++++++++++++++++
- 1 file changed, 16 insertions(+)
-
-diff --git a/net/ipv4/tcp_cubic.c b/net/ipv4/tcp_cubic.c
-index 28011fb1..c6ded6b 100644
---- a/net/ipv4/tcp_cubic.c
-+++ b/net/ipv4/tcp_cubic.c
-@@ -151,6 +151,21 @@ static void bictcp_init(struct sock *sk)
-               tcp_sk(sk)->snd_ssthresh = initial_ssthresh;
- }
- 
-+static void bictcp_cwnd_event(struct sock *sk, enum tcp_ca_event event)
-+{
-+      if (event == CA_EVENT_TX_START) {
-+              s32 delta = tcp_time_stamp - tcp_sk(sk)->lsndtime;
-+              struct bictcp *ca = inet_csk_ca(sk);
-+
-+              /* We were application limited (idle) for a while.
-+               * Shift epoch_start to keep cwnd growth to cubic curve.
-+               */
-+              if (ca->epoch_start && delta > 0)
-+                      ca->epoch_start += delta;
-+              return;
-+      }
-+}
-+
- /* calculate the cubic root of x using a table lookup followed by one
-  * Newton-Raphson iteration.
-  * Avg err ~= 0.195%
-@@ -450,6 +465,7 @@ static struct tcp_congestion_ops cubictcp __read_mostly = {
-       .cong_avoid     = bictcp_cong_avoid,
-       .set_state      = bictcp_state,
-       .undo_cwnd      = bictcp_undo_cwnd,
-+      .cwnd_event     = bictcp_cwnd_event,
-       .pkts_acked     = bictcp_acked,
-       .owner          = THIS_MODULE,
-       .name           = "cubic",